Manufacture of nickel carbonyl



Patented Feb. 9, 1937 UNITED STATES PATENT ()FFICE Birmingham, and

Albert Edward Wallis,

Clydach, England, assignors to The International Nickel Company Inc., New York, N. Y., a corporation of Delaware No Drawing. Application November 22, 1934, Serial No. 7 54,335. In Great Britain November 2 Claims.

This invention relates to the manufacture of nickel carbonyl by treating nickel mattes or similar materials with carbon monoxide under pressure. In order to obtain the most complete con- 5 tact between the nickel and carbon monoxide it is desirable that the matte should be in a finely divided state, but it is found that finely divided materials are liable to be carried away by the carbon monoxide, and the dust deposited from the gas either contaminates any carbonyl that has been liquefied or causes inconvenience in the apparatus.

According to the present invention, the matte or other nickel-bearing material is pulverized and then formed into briquettes, pellets or the like. We find that the nickel can in general be as readily extracted from such briquettes or the like as from the powder itself, while the disadvantages of dust are absent.

Before forming the powder into briquettes or the like, it is preferable to damp it with a small quantity of water or a binding liquid, which may advantageously amount to from 2 to 10% of the weight of the dry powder. We have obtained our best results with water, copper sulphate solution of from 1 to 5% strength, sulphuric acid of from 1 to 5% strength, and ammonium sulphate of from 1 to 10% strength. The use of such binding agents is advantageous, because they increase the strength of the briquettes and also afford a very convenient means of introducin catalysts or other substances whose presence is desired, such as soluble sulphates which may be incorporated in calcined and reduced mattes in this way prior to the briquetting. Moreover, the salts and acids referred to above have the additional advantages that they combine chemically with the matte and therefore consolidate the briquette, and also act as promoters of the reaction between the nickel and carbon monoxide.

It is preferred to incorporate finely divided copper or iron in the briquettes or the like, so as to form copper or iron sulphide and thus permit more nickel to be extracted by the carbon monoxide. This can be done in a very simple manner by means of the invention, and it is not necessary to smelt the matte and metal as has been proposed previously. Similarly agents such as precipitated NiS, which accelerate the extraction of the nickel, can conveniently be added as fine powders to the ground matte before briquetting. In this way intimate admixture of the agent and the matte is obtained without lessening the efficacy of the accelerator as would be the case if the materials were smelted together. The

use of binding agents is found to be of particular value when metal powders are incorporated in the briquette.

The maximum crushing strength is developed by ageing the briquettes or the like. This may be effected by allowing them to stand for from one to four weeks at atmospheric temperature or by drying them at a raised temperature for some 24 to 48 hours.

In the formation of the briquettes or the like, the pressure may vary from about 5 tons per square inch upwards, but generally it is unnecessary to exceed 20 tons per square inch. If the briquettes are comparatively large, they may be broken down into smaller pieces of, say about one'cubic centimetre.

In order that the invention may be clearly understood and readily carried into eifect, two examples will now be given.

Example 1.-A quantity of nickel sulphide matte in admixture with copper was moistened with water equal to 5% of the weight of the powder. Thereafter the damp matte-copper mixture was compressed into 20-gramme briquettes under a pressure of tons per square inch, and dried at 60 C. for hours. It was found that about 90% nickel could then be extracted after about 10 hours treatment with carbon monoxide.

Example 2.-A mixture similar to the above was moistened with a 5% aqueous solution of sulphuric acid until it had absorbed 4% of its own weight. It was then compressed into briquettes under a pressure of 12 tons per square inch, and the resultant briquettes were allowed to age at ordinary air temperatures. It was found that the strength of these briquettes progressively increased up to one months ageing.

These fully aged briquettes were exceedingly strong and had an apparent density of nearly 5.

We claim:

1. A process of manufacturing nickel carbonyl from nickel mattes and similar materials of nonmetallic character which comprises pulverizing a nickel matte to a powder, moistening said powder with a dilute aqueous solution of sulphuric acid equal to about 4% of the weight of the powder, forming said powder into solid briquettes, arranging said briquettes in a mass substantially free from powdered matte, and passing carbon monoxide through said mass of briquettes while under pressure to form nickel carbonyl whereby an extraction of practically all of the nickel may be effected.

2. A process of manufacturing nickel carbonyl from nickel mattes and similar materials of nonmetallic character which comprises pulverizing a nickel matte to a powder, incorporating a binding agent capable of promoting the reaction between carbon monoxide and nickel in said powder, forming said powder into solid briquettes, arranging said briquettes in a mass substantially free from powdered matte, and passing carbon monoxide through said mass of briquettes while under pressure to form nickel carbonyl whereby an extraction of practically all of the nickel may beeffected.

CHARLES F. R. HARRISON. ALBERT EDWARD WALLIS. 

